Screws, bolts, screw rods or hooks are the most basic and most important mechanical parts, which are used in aerospace, medical, heavy industry or people's livelihood industry. However, in the long-term use, they are proned to damage by fatigue, stretching, bending, extrusion or fracture.
Generally, there is no sensor that is designed to build inside those essential parts for damage detection. The most common way used in the industry for achieving such damage detection is by installing an addition sensor, which can be extremely inconvenient to use. In addition, those additional sensors may require to be replaced in a regular base or may not be replaced until themselves are damaged. However, there are some working environments where even a simple condition caused by damaged part is not allowed, such as aircrafts, nuclear power plants, chemical factories, heavy-duty machineries, harbors, or power plants.